The most conventional method for manufacturing a twisted yarn comprises in a first step the manufacture of spun fibers with a suitable spinning device, for example, rotary spinning devices, frictional spinning devices or annular spinning devices, from dissolved fiber material. In a subsequent method step the spun fibers are twisted in a twisting device, for example, a two-for-one twisting device to a twisted yarn. For the manufacture of a twisted yarn it is thus common to provide individual, separate spinning devices on the one hand and a twisting machine on the other hand. With respect to apparatus requirements as well as with respect to the operational sequence this conventional arrangement is very complicated.
The present invention relates to a new approach in which spinning devices are to be integrated into a twisting device operating substantially according to the two-for-one twisting method such that in a continuous operation the spun yarns which are produced by the spinning devices are directly thereafter combined to a yarn and then subjected to a two-for-one twisting operation in order to produce a twisted yarn.
An important element of the two-for-one twisting method is the yarn balloon in which the yarn rotates about the stationary spool pot of the twisting spindle to form an envelope that in the prior art has been considered to be impenetrable with respect to guiding therethrough material flows such as the fiber material in order to enter the space defined by the yarn balloon.
A first attempt to solve this problem of introducing material flows into the space defined by the yarn balloon is disclosed in German patent 37 21 364. In this known method a flow medium is introduced into the space delimited by the yarn balloon without any disturbance of the yarn balloon whereby the spindle rotor is provided with a plurality of spoke-like arranged guide vanes and the yarn guiding channel extends through one of these guide vanes. The flow medium to be introduced into the space defined by the yarn balloon is, in the case of a two-for-one twisting spindle, conditioned air or a two-phase medium such as droplets suspended in air which produce special effects on the yarn to. It is also disclosed in this publication that with this method fiber material can be introduced into the space defined by the yarn balloon.
It is an object of the present invention to provide a method for manufacturing a twisted yarn from at least two yarn components whereby dissolved fiber material is to be introduced to the twisting spindle and the finished twisted yarn is to be removed from the twisting spindle.
In German Offenlegungsschrift 1 785 366 published in 1972 a spinning method is disclosed which at the time was termed "element spinning" in which the fiber material is arranged in a fiber band which is then rotated to form a rotating balloon. For each revolution of the balloon at least two twists are imparted to the fiber band and the finished yarn is removed from the spindle. The device for performing this known spinning process comprises a spinning chamber which is arranged on a spindle. The fiber material is introduced into the spinning chamber via a fiber inlet tube that is arranged coaxial to the spindle axle and is radially guided through a channel extending through the spindle rotor. Within the spinning chamber a collector ring for the fiber material is provided and the fiber material is formed to a roving. The stretched fiber band is then guided through a channel arranged within the spindle axle where a first twist is imparted to the fiber band. The fiber band exits in the radial direction and enters a yarn balloon which rotates about the spinning chamber. Within the yarn balloon a second twist is imparted to the fiber band.
This principle is also discussed in German Publication 4 023 397 (1992) in which again a method for spinning of fibers to a yarn as well as a spinning device for performing the method is disclosed. The fiber material is introduced into the spinning rotor and the removed yarn exiting from the removal opening is guided coaxially about the spinning rotor in a counter rotational direction in an arc. In the device for performing this known spinning method the spinning rotor is supported in a double twisting rotor which itself is rotatably supported in a stationary housing. The yarn removed from the spinning rotor is guided through a removal channel arranged within the double twisting rotor and extending in an arc about the spinning rotor to the common axis of the spinning rotor and the double twisting rotor and is guided upwardly through the drive device of the double twisting rotor. Along this path the yarn is provided with a second twist. The fiber material is fed to the spinning rotor with a feed channel arranged within the double twisting rotor whereby the inlet opening of the feed channel is symmetric and the outlet opening of the feed channel is eccentric to the axis of the double twisting rotor.
A method for manufacturing a twisted yarn from at least two yarn components in which dissolved fiber material is fed to the twisting spindle and the finished, twisted yarn is removed from the spindle is not known in the prior art.